Problem: Recently, Anton has found a set. The set consists of small English letters. Anton carefully wrote out all the letters from the set in one line, separated by a comma. He also added an opening curved bracket at the beginning of the line and a closing curved bracket at the end of the line. 

Unfortunately, from time to time Anton would forget writing some letter and write it again. He asks you to count the total number of distinct letters in his set.

Input

The first and the single line contains the set of letters. The length of the line doesn't exceed 1000. It is guaranteed that the line starts from an opening curved bracket and ends with a closing curved bracket. Between them, small English letters are listed, separated by a comma. Each comma is followed by a space.

Output

Print a single number — the number of distinct letters in Anton's set.

Examples

Input

{a, b, c}


Output

3


Input

{b, a, b, a}


Output

2


Input

{}


Output

0

Solution (in JAVA):

Solution:
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;


public class Main {
    public static void main(String[] args) {
        new Main().run();
    }


    private IO io = new IO();
    private String[] tokens;
    private Set<String> set;


	public Main() {
		String s = io.getLine();
        int l = s.length();
        tokens = s.substring(1,l-1).split(", ");
        set = new HashSet<String>();
	}


	private void run() {
        for (String t: tokens) { if (!t.isEmpty()) { set.add(t); } }
        io.print(set.size());
	}




	// ----------------------------------------------------------------------



    public class IO {
        private final BufferedReader in;
        private final PrintWriter out;
        private String[] tokens;
        private int currentToken;


        public IO() {
            tokens = new String[0];
            currentToken = 0;
            in = new BufferedReader(new InputStreamReader(System.in));
            out = new PrintWriter(System.out);
        }


        public int getNumItems() {
            return tokens.length;
        }

        public String getLine() {
            tokens = new String[0]; currentToken = 0;
            String s = readLine();
            tokens = new String[0]; currentToken = 0;
            return s;
        }

        public String getString() {
            prepare();
            if (tokens.length == 0) { return null; }
            return tokens[currentToken++];
        }

        public int getInteger() {
            String s = getString();
            int n;
            try { n = Integer.parseInt(s); } catch (NumberFormatException e) { n = 0; }
            return n;
        }


        public long getLong() {
            String s = getString();
            long n;
            try { n = Long.parseLong(s); } catch (NumberFormatException e) { n = 0; }
            return n;
        }

        public double getDouble() {
            String s = getString();
            double r;
            try { r = Double.parseDouble(s); } catch (NumberFormatException e) { r = 0.0; }
            return r;
        }


        public int[] getIntegerArray(boolean oneIndexed) {
            prepare();
            int l = getNumItems();
            int offset = oneIndexed ? 1 : 0;
            int[] v = new int[l + offset];
            for (int i = 0; i < l; i++) {
                v[i + offset] = getInteger();
            }
            return v;
        }
        public int[] getIntegerArray() { return getIntegerArray(false); }

        public List<Integer> getIntegerList(boolean oneIndexed) {
            prepare();
            List<Integer> list = new ArrayList<Integer>();
            for (int n: getIntegerArray(oneIndexed)) { list.add(n); }
            return list;
        }

        public List<Integer> getIntegerList() { return getIntegerList(false); }

        // ---------------------------------------------------------

        public void print(Object o) {
            out.print(o);
            out.flush();
        }

        public void println(Object o) {
            print(o); out.println(); out.flush();
        }


        // -----------------------------------------------------------------

        private void prepare() {
            if (currentToken < tokens.length) { return; }
            readLine();
        }


        private String readLine() {
            String s = "";
            try {
                s = in.readLine();
                tokens = s.split(" ");
            } catch (Exception e) {
                tokens = new String[0];
            }
            currentToken = 0;
            return s;
        }

    }


}